Fuel injection system

Patent metadata

Field	Value
Publication number	US-12366221-B2
Application number	US-202218564235-A
Country	US
Kind code	B2
Filing date	Feb 21, 2022
Priority date	Jun 21, 2021
Publication date	Jul 22, 2025
Grant date	Jul 22, 2025

Abstract

An object of the present invention is to provide a fuel injection system capable of suppressing an occurrence of distortion in an injector during assembly of components. A fuel injection system ( 3 ) includes: a bracket ( 5 ) which is fixed to a cylinder head ( 21 ) of an engine ( 2 ); a fuel accumulator ( 6 ) which is supported by and fixed to the bracket ( 5 ) and which accumulates pressure of fuel supplied from a fuel pump; and an injector ( 7 ) which is directly connected to the fuel accumulator ( 6 ) and mounted to the cylinder head ( 21 ) and which injects the fuel, supplied from the fuel accumulator ( 6 ), into a combustion chamber. At least one of the fuel accumulator ( 6 ) and the bracket ( 5 ) has guide members ( 64, 513 ) which guide the injector ( 7 ) to a mount position on the cylinder head ( 21 ).

First claim

The invention claimed is:

1. A fuel injection system injecting fuel into a combustion chamber of an engine, the fuel injection system comprising: a bracket which is fixed to a cylinder head of the engine; a fuel accumulator which is supported by and fixed to the bracket and which accumulates pressure of the fuel supplied from a fuel pump; an injector which has a cylindrical shape extending in an injector axis, is directly connected to the fuel accumulator in a manner of being allowed to shift along the injector axis with respect to the fuel accumulator so that a position of the injector relative to the fuel accumulator is not determined, and is configured to be mounted to the cylinder head and which injects the fuel, supplied from the fuel accumulator, into the combustion chamber wherein the injector has a proximal end and a distal end in the injector axis, the proximal end facing the fuel accumulator and the distal end facing the cylinder head, and a biasing member which is configured to generate a biasing force due to a deformation of the biasing member and attached to the injector at a side of the proximal end of the injector, wherein the fuel accumulator is fixed to the bracket by using first fastening members, wherein the injector axis of the injector is arranged in the same orientation as the first fastening members such that the injector shifts in the same direction as the first fastening members in correspondence with a movement of the fuel accumulator, the bracket is fixed to the cylinder head by using second fastening members, the bracket has first fixing portions which mesh with the first fastening members, second fixing portions each having a hole through which each of the second fastening members passes, and a reinforcing portion which connects and reinforces the first fixing portions and the second fixing portions that are adjacent to each other, and the bracket is formed in a ladder shape or a grid shape, the injector passes through gaps formed in the bracket which is formed in the ladder shape or the grid shape, and the injector is mounted to the cylinder head by the distal end of the injector being inserted into an insertion hole formed in the cylinder head when the fuel accumulator is fastened to the bracket using the first fastening members, the biasing member is deformed by being pressed by the fuel accumulator such that the biasing force, which is generated due to the deformation of the biasing member, presses the injector toward the cylinder head such that the position of the injector relative to the fuel accumulator is determined and the injector is sandwiched between the fuel accumulator and the cylinder head.

2. The fuel injection system according to claim 1 , wherein
the reinforcing portion is a first reinforcing portion, and
the bracket further includes a second reinforcing portion which connects and reinforces the first fixing portions that are adjacent to each other and a third reinforcing portion which connects and reinforces the second fixing portions that are adjacent to each other.

3. The fuel injection system according to claim 1 , wherein
the first fastening members pass through, from above, holes formed in the fuel accumulator and mesh with the first fixing portions, and
the second fastening members pass through, from above, the holes formed in the second fixing portions and mesh with the cylinder head.

4. The fuel injection system according to claim 1 , wherein a fastening surface which comes into contact with the bracket and which is fastened in the fuel accumulator is a same surface as a positioning surface which comes into contact with the injector and which determines a position of the injector in the fuel accumulator.

5. The fuel injection system according to claim 1 , wherein at least one of the fuel accumulator and the bracket has a guide member which guides the injector to a mount position on the cylinder head.

6. The fuel injection system according to claim 5 , wherein
the guide member has
a protruding portion provided on one of the fuel accumulator and the bracket, and
a recessed portion which is provided on the other of the fuel accumulator and the bracket and into which the protruding portion fits.

7. The fuel injection system according to claim 6 , wherein
a direction in which the protruding portion fits into the recessed portion is parallel to a direction of the injection axis in which the injector is inserted into the insertion hole.

8. The fuel injection system according to claim 7 , wherein the cylinder head has a sleeve which is press-fitted into the insertion hole and which determines a position of insertion of the injector into the insertion hole.

9. The fuel injection system according to claim 6 , wherein the guide member has the protruding portion in plurality and the recessed portion in plurality such that each of the plurality of recessed portions is fitted by each of the plurality of protruding portions.

10. The fuel injection system according to claim 6 , wherein when the injector is mounted to the cylinder head, the protruding portion starts to fit into the recessed portion before a position of the injector relative to the cylinder head is determined.

Assignees

• Kubota Kk

Inventors

• Tamura Akira
• Oso Hiroki
• Nagai Naotaro
• Matsunobu Shingo
• Tennomi Masanari

Classifications

• F02M2200/40

  Fuel-injection apparatus with fuel accumulators, e.g. a fuel injector having an integrated fuel accumulator · CPC title

• F02M2200/857

  characterised by mounting fuel or common rail to engine · CPC title

• F02M2200/855

  using clamp elements or fastening means, e.g. bolts or screws · CPC title

• F02M55/025

  Common rails · CPC title

• F02M61/14 Primary

  Arrangements of injectors with respect to engines; Mounting of injectors · CPC title